SDL fullscreen program swapping problem

Hi,

I’m having problems with an app I’m writing. It consists of two
programs, both using fullscreen SDL & OpenGL. The first app is a
selection program to run the second app (which will later be a range of
apps). When the second app needs running I use SDL_Quit, fork and exec
to start the second app, then the parent waits for the child to exit.
The child app runs fine, but when it returns to the parent it crashes
out with the following error message -

Xlib: sequence lost (0x10008 > 0x21) in reply type 0x1!
Xlib: sequence lost (0x10009 > 0x9) in reply type 0x0!
XError of failed request: BadImplementation (server does not support
operation)
Major opcode of failed request: 20 (X_GetProperty)
Minor opcode of failed request: 9
Current serial number in output stream: 9
fxmesa: Receiveed a not handled signal 11

Does this mean that X does not support doing this, or that I should do
it in a different way? Will a better version of XFree86 (using 3.3.5-3)
fix it?

Any help will be much appreciated…

TIA

Mat Tivey